Method for labeling with tritium

Abstract

The present invention provides a tritium-labeling method which allows the introduction of tritium at the last stage of preparation and thus the preparation of the tritium-labeled compound having a high specific radioactivity, and said compound prepared by the method.

1 . A method for preparing a tritium-labeled compound characterized by reacting an organic compound with a tritium-labeled hydride reagent in the presence of a solvent and a catalyst.  
     
     
         2 . A method as claimed in  claim 1  characterized by reacting an organic compound which has a leaving group with a tritium-labeled hydride reagent in the presence of a solvent and a catalyst to substitute the leaving group with tritium.  
     
     
         3 . A method as claimed in  claim 1  or  2  wherein the organic compound is a compound reduced by a catalytic reduction.  
     
     
         4 . A method as claimed in  claim 3  wherein the compound reduced by a catalytic reduction is a compound having a nitro group, triple bond, double bond, and/or benzyl ether in its molecule.  
     
     
         5 . A method as claimed in  claim 1  or  2  wherein the catalyst is a palladium catalyst.  
     
     
         6 . A method as claimed in  claim 5  wherein the palladium catalyst is tetrakis(triphenylphosphine)palladium.  
     
     
         7 . A method as claimed in any one of claims  1 ,  2 ,  4  or  6  wherein the tritium-labeled hydride reagent is NaB 3 H 4  and/or NaB(OMe) 3   3 H.  
     
     
         8 . A method as claimed in  claim 7  wherein the tritium-labeled hydride reagent is NaB 3 H 4 .  
     
     
         9 . A method as claimed in any one of claims  2 ,  4 ,  6  or  8  wherein the leaving group is halogen or sulfonyloxy group.  
     
     
         10 . A method as claimed in any one of claims  1 ,  2 ,  4 ,  6  or  8  wherein the process is conducted under an inert gas atmosphere.  
     
     
         11 . A method as claimed in  claim 10  wherein the inert gas is nitrogen or argon.  
     
     
         12 . A method as claimed in any one of claims  1 ,  2 ,  4 ,  6 ,  8  or  11  wherein the solvent is dimethylformamide.  
     
     
         13 . A tritium-labeled compound which is obtained according to a method as claimed in any one of claims  1 ,  2 ,  4 ,  6 ,  8  or  11 .  
     
     
         14 . A method for establishing pharmacokinetics in which a tritium-labeled compound obtained according to a method as claimed in any one of claims  1 ,  2 ,  4 ,  6 ,  8  or  11  is used.  
     
     
         15 . A screening method for identifying a new useful compound in which a tritium-labeled compound obtained according to a method as claimed in any one of claims  1 ,  2 ,  4 ,  6 ,  8  or  11  is used as a labeling ligand for a known receptor.  
     
     
         16 . A screening method of identifying an unknown protein in which a tritium-labeled compound obtained according to a method as claimed in any one of claims  1 ,  2 ,  4 ,  6 ,  8  or  11  is used as a labeling substance for a bioactive compound.  
     
     
         17 . A compound which is obtained according to a screening method as claimed in  claim 15 .  
     
     
         18 . A protein which is obtained according to a screening method as claimed in  claim 16 .  
     
     
         19 . A method for tritium-labeling an organic compound characterized by reacting an organic compound with a tritium-labeled hydride reagent in the presence of a solvent and a catalyst.